His former manager, Tom Vance of Beaumont, who first met Karras, who was 77, as a representative for the National Football League's players' association, described his friendship with the 6-foot, 2-inch, 250-pound Karras as sort of a second marriage.

"I was with him all the time on the road," Vance said. "We talked every week, but he'd forget he had called me. I saw him in April and got to spend a couple of days with him.

Vance remembers Karras' sense of humor, like the time he showed up for an appearance on The Tonight Show when it still was broadcast from New York, wearing rumpled clothes and a tie so wide it looked like a bib, and managed to send host Johnny Carson into "ballistic" fits of laughter. Karras' appearance bumped another guest, "Exorcist" author William Peter Blatty, to another night because Carson wanted to keep Karras on, Vance said.

Later that evening, at dinner with sportscaster Howard Cosell and writer George Plimpton, whose book "Paper Lion" was about Plimpton's experience researching NFL life, they told Karras he'd be getting calls from producers, Vance said.

Karras also appeared at a benefit "roast" for Walter Umphrey and showed up with a stack of books under his arm, all about Babe Zaharias, as if he were to give a talk about her, and instead inserted the name "Walter Umphrey" for Babe Zaharias.

"He was a great guy and a great friend," Vance said.

Karras played 12 seasons with the Lions from 1958 to 1970, missing the 1963 season after NFL Commissioner Pete Rozelle suspended him and Paul Hornung of the Green Bay Packers for betting on other teams' games. He was "one of the fiercest members" of the Lions' defensive unit of the 1960s who "used his stocky build to bull rush offensive lines," the team says on its website. He was named to the Pro Bowl in 1961, 1962, 1963 and 1966. The Pro Football Hall of Fame included him on its All-Decade Team of the 1960s.

He was also among 3,000 former players in the "mass concussion" lawsuit against the NFL.